1. Field of the Disclosure
This disclosure generally relates to an optical system and, more particularly, to a miniaturized optical system and a portable electronic device capable of controlling the illumination light shape and the detection field of view.
2. Description of the Related Art
With the smart phone products becoming more diverse, the user-friendly operation and the power saving have always been important issues. For example, the gesture recognition function may be applied to the smart phone so as to improve operable functions and the operational convenience. The proximity detection function may also be applied to the smart phone in order to save power by disabling the screen when the user is answering an incoming call. These functions are generally implemented by employing a light source and an image sensor configured to detect reflected light of the light source.
For example, FIG. 1 shows the conventional optical system that is used to implement functions of the gesture recognition and the proximity detection. The conventional optical system 9 includes a light source 91, a sensor 92 and a glass cover 93. The light source 91 is configured to illuminate an object in front of the glass cover 93 to allow the object to generate reflected light. The sensor 92 is configured to detect the reflected light from the object so as to accordingly perform the gesture detection or the proximity detection.
However, a part of light emitted from the light source 91 may be reflected by total reflection inside the glass cover 93, e.g. a light beam 911, or directly reflected by the surface of the glass cover 93, e.g. a light beam 912, and directly received by the sensor 92 without passing through the glass cover 93 thereby causing interference to the image outputted by the sensor 92. Therefore, conventionally in order to eliminate the interference from stray light, e.g. the light beams 911 and 912, a secondary optics lens 94 is arranged in front of the light source 91 or the sensor 92 so as to adjust the illumination light shape and the detection field of view. However, the secondary optics lens 94 has a larger thickness and is difficult to be miniaturized, especially not following the trend of miniaturization of portable electronic devices nowadays.
Accordingly, the present disclosure further provides a miniaturized optical system and a portable electronic device that may control the illumination light shape and the detection field of view according to the designation so as to fulfill the requirement of miniaturization and low cost.